Balance Sheet
| Concept | As at 2024-03-31 | As at 2023-12-31 | 
|---|---|---|
| Balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | 
                                                18,469,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,844,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and deposits | 
                                                3,413,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,289,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Securities | 
                                                4,610,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Supplies | 
                                                28,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                470,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                345,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -7,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings | — | — | 
| Buildings, net | 
                                                6,624,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,654,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                8,196,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,196,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                16,383,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,476,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other, net | 
                                                1,562,965,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,625,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Own-used assets | ||
| Intangible assets | 
                                                167,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                176,876,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Investments and other assets | ||
| Investment securities | 
                                                1,681,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,544,623,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                3,287,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,005,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                610,518,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                470,042,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,038,186,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,033,938,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                19,838,175,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,659,440,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other assets | — | — | 
| Current assets | ||
| Other assets | ||
| Assets | 
                                                38,307,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,504,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Non-current liabilities | ||
| Non-current liabilities | 
                                                3,311,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,340,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term borrowings | 
                                                500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax liabilities | 
                                                6,127,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                115,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                374,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                398,136,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                7,942,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,625,392,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                2,800,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                605,787,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                2,052,357,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,831,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | ||
| Current portion of long-term borrowings | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                498,757,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                125,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Liabilities | 
                                                11,253,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,965,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other liabilities | — | — | 
| Other liabilities | — | — | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                25,981,423,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,555,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                3,173,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,173,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                3,352,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,352,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                19,596,166,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,170,115,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -140,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -140,477,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                1,071,028,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                982,412,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                859,614,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                762,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                27,053,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,538,803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                38,307,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,504,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Valuation and translation adjustments | ||
| Shareholders' equity | ||
| Capital surplus | ||
| Retained earnings |